Fevurly RD, Hasso S, Fye A, Fishman SJ, Chan J. Novel zebrafish model reveals a critical role for MAPK in lymphangiogenesis.
J Pediatr Surg 2012;
47:177-82. [PMID:
22244413 PMCID:
PMC3662220 DOI:
10.1016/j.jpedsurg.2011.10.035]
[Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/01/2011] [Accepted: 10/08/2011] [Indexed: 01/08/2023]
Abstract
PURPOSE
Lymphatic disorders are poorly understood with few animal models. We designed a novel assay to measure lymphatic development using transgenic zebrafish with fluorescently labeled endothelial cells. Two major branches of the vascular endothelial growth factor receptor (VEGFR) signaling pathway were examined: the MAPK and PI3K pathways.
METHODS
Direct visualization of lymphatic development was performed in control embryos or under chemical inhibition. Treatment involved a 6-hour pulse of inhibitor at 3 days postfertilization. Fish were analyzed for the presence of the thoracic duct (TD) at 4 days postfertilization (n > 100 specimens).
RESULTS
Thoracic duct formation was prevented using selective inhibitors against kinases (MAPK, PI3K/TOR, or VEGFR). These kinases were important for TD formation because the lymphatic vessel failed to form in most of treated animals. Remarkably, MAPK pathway inhibition most robustly reduced lymphangiogenesis, demonstrated by a lack of lymphatic endothelial cells.
CONCLUSION
We conclude that MAPK pathway function downstream of the VEGFRs is crucial at the early stages of TD development. This study provides a novel animal model and a potential target pathway for further investigation. We suggest further examination of MAPK pathway deregulation as a potential mechanism underlying lymphatic disease in humans.
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